tests-vitestlisted

# Frontend unit tests: Vitest Write and run frontend component and unit tests using Vitest conventions. Run them with the project's own unit-test script if it defines one (e.g. a `test` / `test:unit` npm script that invokes Vitest); otherwise invoke Vitest directly (`npx vitest run`). The `Frontend test command` slot is the **e2e** command — don't use it for unit tests. - Test files are typically co-located with their source file (`Button.test.tsx` next to `Button.tsx`) or collected under `src/__tests__/`. Check the project's `vitest.config.ts` (or `.js`/`.mjs`) for the actual `include` pattern before creating a new file. - Use `@testing-library/react` (`render`, `screen`) with `userEvent` from `@testing-library/user-event` for component tests; use plain `vi.fn()` / `vi.spyOn()` for unit mocks and `vi.mock()` for module mocks. - Prefer queries that reflect how users perceive the UI (`getByRole`, `getByLabelText`, `getByText`) over implementation-detail selectors (`getByTestId`, CSS class). - On re-verify, run only the failing test(s) — pass the test file path and/or `-t` / `--testNamePattern` to match by name — not the whole suite. `--reporter` only changes output format; it does not filter which tests run.